Lewis said general farm work was time sensitive and it was not necessarily appropriate or possible for farmers to be able to allow work to stop so employees could talk to union workers at any time ... "Think milking cows or shearing sheep."
Lewis said there was also the risk of someone you didn't know turning up and claiming they were a union official when they might not be.
"Rural crime prevention is seriously under resourced and while it's like that why should farmers give open access to their businesses to people they may be unfamiliar with in what often is also their family homes?
"While farms are workplaces they are also homes and it's common courtesy to give a farmer a heads up before coming on the farm.
"Although, we do agree that farmers, or any business owners, should not be able to unreasonably restrict access."
Lewis acknowledged the Government's work on this Bill and thanked them for working with the advocacy organisation to address its concerns.
"This is a big win for Feds advocacy."
New Zealand First leader Winston Peters said changes made to the controversial Workplace Relations Bill gave small business a "fair go".
The bill, which was supported by all three Government partners at first reading, has been the subject of horse-trading between Labour and New Zealand First since it returned from a select committee with few material changes in September.
At that time Peters described it as a work in progress but today the bill was back before Parliament, with changes outlined by Workplace Relations Minister Iain Lees-Galloway in supplementary order paper.
Another change was around the multi-employer collective agreement (Meca) provisions.
Employers had a responsibility to enter into bargaining but were not compelled to settle an agreement, based on reasonable grounds.